An epifluorescence microscope is similar to a conventional reflecting optical microscope in that both microscopes illuminate the sample and produce a magnified image of the sample. An epifluorescence microscope, however, uses the emitted fluorescent light to form an image whereas a conventional reflecting optical microscope uses the scattered illumination light to form an image. The epifluorescent microscope uses a higher intensity illumination, or excitation, light than a conventional microscope. The higher intensity excitation light is needed to excite a fluorescent molecule in the sample thereby causing the fluorescent molecule to emit fluorescent light. The excitation light has a higher energy, or shorter wavelength, than the emitted light. The epifluorescence microscope uses the emitted light to produce a magnified image of the sample. The advantage of a epifluorescence microscope is that the sample may be prepared such that the fluorescent molecules are preferentially attached to the biological structures of interest thereby producing an image of the biological structures of interest.